The present invention relates to a method and apparatus for delivery of multi-component adhesive systems to a work site and in particular, to a cartridge type tool for simultaneously mixing and extruding the mixed adhesive components to such places as voids, holes and apertures in building and masonry structures.
Two part epoxy adhesive systems are widely used. In such systems, the resin must be kept separate from the hardener, until virtually the last moment before application, since otherwise, the system would prematurely set and cure. Such separation is insured during transport by storing each component in its own container, generally a relatively rigid cylindrical cartridge having a moveable rear wall. There are many instances however, where the work site onto which or into which the adhesive must be placed, is highly inaccessible or difficult to reach. Thus, the mixing of the two components, close to the work site, is most difficult and sometimes impossible. Many of these sites, particularly in the construction of building and masonry structures, also require the adhesive system to be applied under pressure to insure complete filling of the holes or voids.
Reference can be made to my earlier applications Ser. No. 047,167 filed May 7, 1987 and Ser. No. 135,662 filed Dec. 21, 1987 which describe a process for securing and anchoring together building elements, such as masonry stone facia and the like wherein self-curable hardenable adhesives are applied into hollow chambers, holes or the like, either alone or in combination with mesh sleeves and anchoring rods which eventually become permanently imbedded into the adhesive. The processes described in the foregoing applications are explanatory of the uses for plural component adhesive systems wherein mixing and extrusion of the adhesive is most effective at the work site. Of course, it will be understood that such exemplification is not exclusive of other systems or applications for which a similar need exists. Therefore, there is a serious requirement for highly portable mixing and extrusion system, to which the present invention is addressed.
One known portable epoxy injection apparatus makes use of a two cartridge system wherein the cartridges, one containing the first component and the other containing the second component are placed in a dispenser which uses two parallel pistons driven by a single drive shaft to deliver both components to a static mixing nozzle. A potential problem exists in that two components generally have widely varying viscosities creating a load imbalance between the two pistons. This may cause dispenser to malfunction and/or cartridge to rupture or result in improper mix ratio entering the static mixing nozzle.
Another known injection system makes use of a single coaxial body where the cartridge containing the first component is arranged within the cartridge containing the second component thus defining a cylinder within the cylinder arrangement. This arrangement is used in conjunction with a dispenser which utilizes a single drive shaft with two coaxial plungers attached which force the two components from the coaxial cartridge into a static mixing nozzle. A problem exists with this arrangement for materials of widely different thicknesses or viscosities causing a pressure imbalance wherein the wall of the inner chamber of the cartridge will collapse or inflate to the point of rupture. In a less severe situation, the material may flow from the cartridge at an improper mix ratio as it enters the nozzle.
Generally, all the existing portable epoxy injection equipment lack the ability to balance the two disparate fluids of the resin and hardener. In existing equipment, differences between fluid component thickness cause imbalance in the dispenser and the cartridge cavities resulting in either a cartridge rupture and/or dispenser malfunction. Each condition results in mix ratio variations entering the static mixing nozzle. This can and does cause performance failure when it goes unnoticed.
The foregoing problems are somewhat exacerbated by the fact that the conventional component cartridges are made of thin walled plastic, paper, or plastic impregnated paper, where materials are elastic under internal pressure and relatively easy to rupture or collapse.
It is the object of the present invention to provide an improved portable extrusion system for at least two component adhesive systems.
It is a further object of the present invention to provide simple, economic and easily manipulatable apparatuses delivering two or more component adhesives.
It is a particular object of the present invention to provide a tool for the extrusion of a multi-part adhesive system employing cartridges arranged for balanced extrusion.
It is yet another object of the present invention to provide a tool for the extrusion of multi-part adhesive systems in which rupture or collapse of the component cartridges are prevented.
The foregoing objects and advantages, as well as others, will be apparent from the following disclosure and from the embodiments of the invention as illustrated in the accompanying drawings.